Radiation Effects in Hg1-x Cdx Te

Radiation effects studies have been performed at 10 and 80°K in bulk Hgo.8CdO.2Te. These studies concentrated on radiation damage to the material properties, such as lifetime, carrier density, mobility, and electrical conductivity, which are important in determining the performance of an Hg0.8CdO.2Te infrared detector. In n-type material, an increase in carrier density was observed for electron, gamma, and neutron irradiations at both 10 and 80°K. At 10°K, a carrier introduction of +16 cm-1 was measured for 5-MeV electrons, compared to an introduction rate of ~3 cm-1 for fusion neutrons. In the relatively uncompensated material used for the study, the lifetime was Auger-limited and exhibited the expected carrier density dependence ( τ ∝ n-2) during electron irradiations at 10 and 80°K. Lifetime damage produced by fission neutrons at 80°K indicated both a Shockley-Read and an Auger component. Application of the radiation effects data to a photoconductive detector with ohmic contacts indicates that a detector operating at a bias level which produces minority-carrier sweepout is substantiallv more radiation-resistant than one operated in the non-sweepout mode.